Lighting system for gaseous illuminating tubes



A. E. NOBLE 1,993,111 LIGHTING SYSTEM FOR GASEOUS ILLUMINATING TUBES March 5, 1935.

. Filed May 19 1953 Patented Mar. 5, 1935 .UNITED STATES IJGHTING SYSTEM FOR GASEOUS ILLUMINATING TUBES Aubrey E. Noble, Snyder, N. Y., assignor to Daylite Tubes, Inc., Buffalo, N. Y., a corporation of New York Application May 19, 1933, Serial No. 671,882

16 Claims. (Cl. 176-124) This invention relates to lighting systems for gaseous illuminating tubes, and particularly to means for striking an arc in said tubes when said tubes are to be used for illumination pur- 5 poses. a

An object of the invention is to provide improved means for automatically striking an arc in a gaseous illuminating tube, which will be fully automatic in action, and relatively simple, detaendable, compact and inexpensive in construcion.

Another object of the invention is to provide improved means for ionizing the gas in a gaseous illuminating tube, of the type utilizing a heated cathode, to strike an arc therein, with which ionization of the gas may be accomplished automatically merely by applying power to the lighting circuit of said tube, with which the ionization of the gas will be delayed for a selected and appreciable interval of time after illuminating current is applied to said tube so that the cathode may be heated to some extent before the arc is struck, which will require a minimum of apparatus, which will automatically reset itself for 5 succeeding operation, and with which the time interval may be selected throughout a considerable range and thus made adaptable to the time required to heat the cathode of the tube approximately to emission temperature.

Another object of the invention is to provide an improved, delayed action, starting tube which may be advantageously used as a part of the are striking mechanism for low voltage gaseous illuminating tubes, and which will be relatively simple,.compact, dependable and inexpensive.

Various other objects and advantages will be apparent from the following description of an embodiment of the invention, and the novel features will be particularly pointed out hereinafter in connection with the appended claims.

In the accompanying drawing:

Fig. 1 is a diagram of a lighting circuit or systern constructed in accordance with this invena system using only one gaseous illuminating tube, or a plurality of tubes connected in any suitable manner. The tube is of the double anode type and the tube 11 is of the single anode type. The lighting current for such a tube is alternating current of any suitable frequency, which is supplied by line wires L and L These two wires are connected, through suitable controlling switches A to the primary winding 12 of a suitable transformer, preferably one of the leakage type, and magnetic shunts may be provided in such a transformer.

The transformer has secondary windings 13 Y and 14 which are connected to one another in series by a wire 15, and together form a main secondary winding. The winding 13 at the end opposite to its connection to the wire 15, is connected by a wire 16 to one of the anodes 17 of the tube 10. The winding 14, at the end which is opposite to its connection to the wire 15, is connected by a wire 18 to the other anode 19 of the tube 10. A suitable condenser 20. is connected between the anodes 17 and 19 of the tube 10 as a power factor correction. A wire 21 connects the cathode 22 of the tube'lO to the anode 23 of the tube 11. A wire 24 connects the cathode 25 of the tube 11 to one end of a choke coil or winding 26, the other end. of that winding being connected by a wire 27 to the wire which connects the secondary windings 13 and 14.

The core 28 of the choke coil is provided with an air gap 29 which is utilized in striking an arc in each tube in a manner that will appear hereinafter. .The cathodes 22 and '25 are ofthe heated type, and are illustrated, for example, as of the filament type receiving their heating current from low voltage windings 30 and 31 respectively,

which are in inductive relation to the other windings of the transformer, but obviously any other type of heated cathode may be employed or other sources of heat or current for such cathodes may be employed.

The transformer acts as a source of current for the lighting circuit, which includes the wires is contained within a gas tight envelope or tube 32, that may, for convenience, be formed of glass. A plurality of conductors 33, 34 and 35 37 is mounted in said globule of glass or insulating member 36 and extends upwardly in the tube so as to serve as a support for certain parts to be described presently and, by reason of the insulating globule or part 36, this support is electrically insulated from the conductor 34.

The conductor 33 extends into the interior of the tube or member 32 and carries a switch arm 38 which is yieldingly and resiliently urged in a direction toward the support 37. This switch arm may be a composite member including a helical spring 39 which is connected at one end to an extension of the conductor 33 and at its other end carries a rod 40. This helical spring allows the flexing of the free end of the switch arm, but provides a resilient urge the support 37. An arm or reasonably stifi wire 41 extends laterally from the rod 40, and carries at its end a contact 42 which engages a stop or contact 43 which, in turn, is carried by a rod or fairly stiff wire 44 that extends laterally from the insulated support 37. The engagement of the contact 42 with the contact or stop 43 limits the movement of the switch arm under the action of the spring 39.

The conductor also extends well into the interior of the tube or envelope 32 and one end of a bimetallic strip, member or arm 45 is attached to and supported by the inner end of this conductor 35-, so as to form a continuation of that conductor. The other end of this bimetallic member or strip 35 carries a contact 46 which is adapted to engage a contact 47' that is carried by an arm or wire 48 projecting from the rod of the switch arm. The bimetallic member is a thermal element, and because of the difference in coeflicients of expansion of the two metals of which it is made, ittends to warp in opposite directions upon changes in temperature. It is so arranged that upon an increase in temperature, it will flex and carry its free end, with the contact 46 thereof, into engagement with the contact 47 that is carried on the switch .arm 48, while the switch arm is engaged with supported at one end or arm by the inner end of the conductor 35, and the other endor arm of the bracket 49 extends into a position adjacent the free end of the bimetallic member or thermal element 45 and serves to limit the flexins movement of the bimetallic member 45 under a. falling temperatm-e. The free end of the bimetallic member 45 is, however, free to flex away from the stop or bracket 49 upon an increase in temperature. A heating coil or resistance element 50 of any suitable material is mounted between the arms of the bracketmember 49 by means of insulating blocks 51, and the upper end of this resistance or heating unit or coil 50 is connected by a wire 52 to an extension of the rod 44 that is carried by. the insulated support 37. This electrically connects unit or element 50.

one end of the heating coil to the stop or contact 43.

The "other end of the heating unit or element 50 is connected by a wire 53 to a wire or arm 54 that extends laterally from the inner end of the conductor 34. It will be observed that the conductor 34 is connected at its inner end to the heating element 50, and the latter is connected at its other end to the limiting stop or contact 43 which engages and limits the movement of the switch arm 38. The switch arm 38 is connected to the conductor 33 .and, therefore, a circuit is established between the conductors 33 and 34, which includes the switch arm, the contacts 42'and 43 and the heater The heater unit or element 50 is disposed in close proximity to the bimetallic arm or member 45, so as to be in heat exchanging relation thereto and thus, when the heating element is operating, the heat radiated therefrom causes an increase in temperature in the'bimetallic member 45, causing the latter to fiex at its free end and carry its contact 46 into engagement'with the contact 47 that is carried by the switch-arm 38.

The engagement of contacts 46 and 47 estab-- lishes a circuit between the conductors 33 and 35 which will be broken as the switch arm 38 coil, with the armature 55 nearest the air gap 29, as shown inFig. l, the armature and switch arm will be attracted in a switch opening direction upon energization of the choke coil winding 26.

All of the parts within the tube or envelope 32 are mounted in such a way, and are made of such a material, that they may be easily degasified by any suitable means, such as by high frequency bombardment. It is very important that substantially all gas and air be removed from the parts in the tube or envelope, and from the walls of the envelope, and in order to remove the last trace of gas, I may also flash oil a getter in the lower part of the tube. The envelope 'or tube is exhausted to a high vacuum, and sealed after .degasifying of the parts and the envelope. The

getter may be of any usual type and material, such as magnesium or barium. It is desirable to have a high vacuum and I have been able to obtain vacuums as high as 25 mm., mercury pressure, and .1 microns of mercury pressure.

In the operation of a lighting system, such as illustrated, let it be assumed that the power lines I. and I are disconnected from the lighting system, in which case no illuminating current will be passing through the tubes 10 and 11. The

choke coil is deenergized and the switch arm 38 is yieldingly urged against the stop 43, which is the position shown in the drawing. No current is now flowing through the tungsten heating Current immediately flows through the file.- ment cathodes 22 and 25 to heat them, but current induced in windings 13 and 14, although impressed upon the lightingcircuit, can not flow through the tubes 10 and 11 until the gases in those tubes are first ionized to strike arcs. Some of the current induced in one of the cathode windings, such as the winding 31, immediately flows through the heater coil 50 by means .of the following circuitz-through wire 24, conductor 33, switch arm 38,1ateral rod or extension 41, contacts 42, 43, supporting rod 44, wire 52, coil 50, conductor 53, arm 54, and conductor 34, back to the other side of the winding 31. Current passing through the coil 50 heats the coil, and

this heat, which is radiated, tends to heat the 14. The current induced in the winding 14 thus passes through the choke coil and energizes it, and when the choke coil 26 is energized the magnetic field set up thereby at the air gap 29 will' attract the armature 55 on the switch arm 38 and move the latter against the resiliency of the spring 39, in a direction to separate the contacts 46 and47 and open the circuit through the choke coil winding.

When this special circuit is opened in this manner by the magnetic attraction of the switch arm 38, the choke coil attempts to discharge its stored up energy, and this discharge does not occur through the special circuit including the contacts 46 and 47 because those contacts have now been separated. Instead, the choke coil discharges its energy as momentary currents through the gaseous illuminating tubes 10 and 11 because, as will be remembered, the choke coil is also in series in the lighting circuit for these tubes 10 and. 11. Since a voltage is already impressed on the tubes 10 and 11 by the currentinduced in the windings 13 and 14, this sudden discharge of energy from the choke coil through the tubes 10 and 11 ionizes the gases in those tubes and thereby strikes arcs in those tubes.

When the arcs strike, the lighting current immediately flows through the lighting circuit and illuminates the tubes. The lighting current then flowing through the choke coil 26 will keep it energized and thus keep the switch arm 38 attracted and in open circuit position. It will be noted that when the switch arm 38 is attractedate an are striking operation, it follows that' during this appreciable time, the currentsflowing in the cathode heatingcircuits will have an opportunity of heating those cathodes to an appreciable extent, and preferably to approximately emission temperatures, before the arcs are struck in the tubes 10 and 11. This delay prevents bombardment of the cold cathodes in the tubes 10 and 11 before the cathodes are up to emission temperatures and thus prevents injury to the tubes.

If cathodes are employed which require a different interval of time in which to heat approximately to emission temperatures, the period of delay may be changed by varying the size of the coil 50 or by varying the quantity of current passing therethrough, such as by a suitable resistance included in series in the circuit of coil 50, or in any other suitable manner. The position of the stop 43 for the switch arm may also be changed so that the bimetallic member 45 will have to flex to a greater or lesser extent upon an increase in temperature before the arcs are struck. The relatively high vacuum in the starter tube or member 32 prevents the energy, that was stored up in the choke coil, from jumping the gap between the contacts 46 and 4'7 but ionizes the gases therein to an extent such that the voltage then available and applied to the tubes 10 and 11 in the lighting circuit will cause the lighting current to flow and maintain the arc.

When-the tubes 10 and llare extinguished, either through failure of power or through intentional opening of the circuit from the power lines L and L to the primary transformer winding 12, the arcs in the tubes 10 and 11 will, of course, disappear andthe lighting current will no longer flow in the lighting circuit. The deenergization of the choke coil wire 26 which results will release the magnetically held switch arm 38, and the latter will thereupon be urged by the spring 39 toward the bimetallic member 45 until stopped lishing the parts in a position to strike a new are with the delayed action, automatically as soon as the current is again restored to the primary winding 12 in the manner hereinabove explained.

It will be understood that various changes in the details, arrangements and shapes of parts, and in the materials utilized, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention, as expressed in the appended claims.

I claim:'- 1. In a lighting system, agaseous illuminating tube of the hot cathode type, a choke coil, a lighting circuit containing said choke coil and tube in series, common means for supplying a current to said lighting circuit and for heating said cathode, a special circuit for passing a current through the choke coil only of said lighting circuit, a magnetic switch in said special circuit, normally urgedto closed positionbut operable to open position by magnetic attraction of said choke coil upon energization of said choke coil, and means controlled by said common means for keeping saidspecial circuit open for aselected and appreciable interval of time after said common means has been operated to cause the heating of said cathode, whereby the ionizaton of gas in said tube to start the flow of lighting current therethrough through the opening of the special circuit of said choke coil may be delayed foran interval of time during which the cathode may be heated approximately to emission temperature.

2. In a fighting system, a gaseous illuminating tube of the type having a heated cathode, a. lighting circuit including said tube, means for heating said cathode, means controlling the operativeness of said heating means, switch controlled means operable in any position and inclination for ionizing the gas in said tube to strike an arc therein, and means automatically operable to close the switch of said switch controlled means and initiate an operation of said ionizing mans for a selected and appreciable interval of time after said controlling means has been operated to start the'heating of said cathode, whereby the striking of an arc in said tube before said cathode has been appreciably heated will be prevented;

3. In a lighting system, a gaseous illuminating tube, a transformer having a primary winding and a secondary winding, a lighting circuit connecting said secondary winding to said tube to pass a secondary current .therethrough, another winding arranged in inductive relation to said windings for heating said cathode by current induced from said windings, a choke coil connected in series with said tube in said lighting circuit, a special circuit for passing a current through the choke coil portion only of said lighting circuit, a magnetic switch included in said special circuit and operable to open position upon energization of said choke coil, and means controlled by said other winding and operable automatically a selected interval of time after current is applied tosaid primary winding for initially closing said 7 special circuit whereby the ionizing of gas in said tube to strike an'arc therein upon the opening of said special circuit through the choke coil' will be delayed for an appreciable interval of time after the heating of said cathode is in-' itiated.

4. In a lighting system, a gaseous illuminating tube having a cathode of the heated type, means for heating said cathode, means controlling the activity. of said heating means, means having a normally open circuit for automatically ionizing the gas of said tube to strike an arc therein, and

.a time delay device operable automatically to close said normally open circuit and cause the striking of said are an appreciable interval of time after said controlling means has initiated the heating of the cathode.

5. In a lighting system, a gaseous illuminating tube having a cathode of the heated type, means for heating saidcathode, means controlling the.

activityof said heating means, means operated by a normally open circuit for automatically ion: izing the gas of said tube to strike an arc therein, and means including a thermal element rendered eifective concurrently with said controlling means, when the latter is operated to initiate a 'heating of said cathode, and operable to close said normally open circuit an appreciable interval of time after said controlling means has started a heating of said cathode, and means automatically operable by passage of current through said tube for opening said normally open circuit.

6. In a lighting system, a gaseous illuminating tube having a cathode of the heated type, a lighting circuit for said tube, means for heating said cathode, means controlling the activity of said heating means, means including'a special circuit for ionizing the gas of said tube to strike an arc therein and including a normally open con trolling switch, a thermal device for closing said switch, and means rendered efi'ective when said controlling means is operated to make said heating means active, for causing amovement of said thermal device in a manner to close said switch an appreciable intervalof time after heating of said cathode has been started, whereby an arc will not be struck in said tube until said cathode has been heated to some appreciable extent.

7. In a lighting system, a'gaseous illuminating tube having a cathode, means for heating said cathode, controlling means for said heating means, a lighting circuit for said tube, means including a circuit and a switch therefor which is normally open when no current is passing through said tube, for striking an arc in said tube and rendered ineffective automatically upon the flow of current in said lighting circuit through said tube, and means for closing said switch to cause the striking of said arc an appreciable interval of time after the heating of said cathode has been started.

8. In a lighting system, a gaseous illuminating tube havinga cathode, means for heating said cathode, controlling means for said heating means, a lighting circuit for said tube, means including a normally open circuit for striking an arc in said tube and rendered ineii'ective automatically upon the flow of current in said lighting circuit through said tube, and a delayed action tlflermal device for closing said normally open circditto initiate the striking oi an arc in said tube an appreciable interval of time after heating of said cathode has been started. v

9. In a lighting system, a gaseous illuminating tube having a cathode, means for heating said cathode, a lighting circuit including said tube,

means for striking an arc in said tube including a switch automatically opened by the flow of current through said tube in said lighting circuit, said switch having a-pair of contacts which engage one another to initiate the striking of an arc, a thermal element supporting one or said contacts and responsive to temperature changes, a heater element disposed in a position to heat said thermal element and cause it to shift its contact into a position to engage the other contact of said switch and initiate a striking of an arc, and means including a circuit for said heating device rendered efiective concurrently with said cathode heating means, and rendered ineffective automatically by the opening of-said switch at the striking of an arc.

10. In a lighting system, a gaseous illuminating'tube, a transformer having a primary wind- .ing and a secondary winding, a fighting circuit for said tube including said secondary winding, means arranged in inductive relation to said windings for heating said cathode by current induced from said windings, a choke coil included 'series in said lighting circuit, a special circuit for passing current from a portion of said secondary winding through said choke coil to energize said,

of said choke coil into open position but yieldingly urged in a closing direction, said switch having a movable member and a cooperating relatively fixed contact, a bimetallic support for said contact and flexing to shift said contact toward said movable member upon an increase'in temperature, a heating unit disposed in heat exchang-. ing relation to said bimetallic support for heating the same, a stop disposed in a position to limit the movement of said movable member toward said contact, a heating circuit including said heater element, said stop, and'said movable switch member, and rendered efiective concurrently with the heating means for said cathode, and rendered ineffective by the separation of said movable member and said stop, whereby the striking of an arc in said tube will be delayed for an appreciable interval of time after current is applied to said primary winding while said cathode is being preliminarily heated to some extent.

11. In a lighting system, a gaseous illuminating tube, a transformer having a primary winding, a main secondary winding, and a cathode winding, a circuit including said cathode winding for heating said cathode by current induced in said transformer, a lighting circuit including said secondary winding and said tube, a choke coil included in series in said lighting circuit, a bimetallic member which changes its shape in response to temperature, a contact shifted by said bimetallic member in a prescribed path, a switch arm resiliently urged in a direction to engage said contact and toward which said contact is moved by said bimetallic member upon an increase in temperature, an armature connected to said switch arm and disposed in magnetic relation to said choke coil, whereby the choke coil, when energized, will attract said armature and 'move the switch arm in a direction away from said contact, a heater element disposed'in heat exchanging relation to said bimetallic member, a stop for limiting movement of said switch arm toward said contact, a heater circuit for said heating element including said stop, said switch arm, said heater element and said cathode winding whereby the current flowing in said heater element circuit will heat said bimetallic member and cause it to move in a direction to carry its contact into engagement with said switch arm when the switch arm is engaging said stop, the

movement of said switch arm out of engagement with said contact also opening said heater circuit, means connecting said switch arm to the end of the choke coil which is connected to the tube, and means connecting said contact to a portion of the secondary winding which is remote from the portion of that winding which is connected directly to the choke coil, whereby when said switch arm engages said contact, a special circuit will be established through said choke coil, and the following attraction of said switch arm by said choke coil will open both the circuit tor the heater element and said special circuit through the choke coil.

12. In a lighting system, a delayed action starter for gaseous illuminating tubes comprising an envelope, a bimetallic member supported at one end by said envelope and free at its other end to flex with changes in temperature, a contact car-,- ried by the free end of said bimetallic member, a switch arm also supported at one end by said envelope and having its free end resiliently urged in a direction toward said contact, and toward which said contact moves with said bimetallic member upon an increase in temperature, a stop limiting the movement of said. switch arm toward said bimetallic member, a heater element disposed in heat exchanging relation to said bimetal member, and connected at one end to said stop, a conductor connected to the other end of said heater element from the exterior of said envelope, an armature carried by said switch arm and free to move with said switch arm in a direction away from said stop, conducting means extending into ber is normally disengaged from said switch arm. 13. In a lighting system, a delayed action starter for gaseous illuminating tubes comprising an envelope exhausted to a relatively high vacuum, a bimetallic member supported at one end by said envelope and free at its other end to flex with changes in temperature, a contact carried by the free end of said bimetallic member, a switch arm also supported at one end by said envelope and having its free end resiliently urged in a direction toward said contact and toward which said contact moves with said bimetallic member upon an increase in temperature, a stop limiting the movement of said switch arm toward said bimetallic member, a heater element disposed in heat exchanging relation to said bimetal member, and connectedat one end to'said stop, a conductor connected to the other end of said heater element from the exterior of said envelope, an armature carried by said switch arm and free to move with said switch arm in a direction away from said stop, conductingmeans extending into said envelope and connected tosaid switch arm,

whereby said switch arm normally is yieldingly urged against said stop and said bimetallic member is normally disengaged from said switch arm.

14. In a lighting system, a delayed action are urged in a direction to engage the moving part of said thermal element, a stop for said switch arm for preventingengagement of the moving part of said thermal element by said switch arm when said thermal element is unheated by said heater element, an electrical connection between said stop and one end of said heater element, a conductor extending from the other end of said heater element through said envelope, a conductor extending from' outside of said envelope to said thermal element, another conductor extending into said envelope and connected to said switch arm, and an armature carried by said switch arm and tree to move with said switch arm in a direction away from said stop, all of the parts within said envelope being thoroughly de-' gasified to remove impurities.

15. In a lighting system for gaseous illuminating tubes, a delayed action are striking device including a gas tight envelope, three conductors extending into said envelope and insulated from one another, an insulating member carried by the inner end of one of said conductors, a support carried by said insulating member, a stop carried by said support, a bimetallic bar anchored at one end to the inner end of another of said conductors and free to flex at its free end, a stop carried by this lastmentioned conductor and disposed in a position to limit flexing of the free end of said bimetal member under a falling temperature, a heater element carried by and insulated from said last mentioned stop, one end of said heater element being connected to the first mentioned stop and the other end of the heater element being electrically connected to the innerend of that conductor which extends into said envelope and carries said insulating member, a switch arm anchored at one end to the inner end of the third the switch arm and slightly spaced from a movable part of said bimetallic member when said arm engages said first mentioned stop and within the path of movement of said bimetal member when the latter flexes upon an increase in temperature, all parts within said envelope being thoroughly degasified to remove impurities, and saidenvelope being exhausted to a relatively high vacuum, whereby arcing between said switch arm and with said bimetallic member or said first men- I,993,1 I I tioned stop will be prevented when said switch arm moves in a direction away from said first mentioned stop.

16. In a fighting system, a gaseous illuminating tube having a cathode of the heated type, means for, heating said cathode, means including a normallyopen circuit for automatically ionizing the gas of said tube to strike an arc therein, a time delay device operable automatically to close said normally open circuit and initiate a striking of said are an appreciable interval of time after the heating of said cathode has begun, and means operable automatically by the flow of current through said tube for opening said normally open circuit and incapacitating said time delay device.

AUBREY E. NOBLE. 

